Eristalis. 415 



— Epistoma with a black middle slripe 11. 



11. Anterior tarsi quite yellow 10. pertinax. 



— Anterior tarsi not quite yellow, only pale at the base 



on raiddle or both pairs 12. 



12. Wings hyaline with a very small stlgmatical dot; ab- 



dominal spots partly or quite shining 11. nemorum. 



— Wings with a more or less distinct, dark fascia, stigma 



longer than broad; abdominal spots dull 12. horticola. 



13. Thorax pale pruinose on the front half, black on the 

 posterior half; hind femora thickened; eye-suture in the 



male short 15. alpinus. 



— Thorax unicolorous, somewhat shining; hind femora not 

 thickened; eye suture in the male not short 14. 



14. Hind femora pale on the basal part in the male, on the 

 basal half in the female; wings hyaline in the male, 

 with a narrow fascia in the female; abdomen in the 



female not quite shining 13. vitripennis. 



— Hind femora in the male quite black or shghtly brownish 

 at the extreme base, in the female yellow at the base; 

 wings with a dark middle blotch, especially large and 

 distinct in the female; abdomen in the female quite 



shining 14. rupium. 



1. E. sepulchralis L. 



[?1758. Linn. Syst. Nat. X, 596 et 1767. XII, 2, 991, 73 et 1761. Fm 

 Suec. 1835 {Musca)]. — 1775. Fabr. Syst. Entom. 772,49 et 1781. Spec. 

 Ins. II, 431, 51 et 1794. Ent. Syst. IV, 303, 91 (Syrphus) et 1805. Syst. 

 Antl. 245,61. — 1822. Meig. Syst. Beschr. III, 383,1. — 1843. Zett. Dipt. 

 Scand. II, 670,16 {Syrphus). — 1862. Schin. F. A. I, 333. — 1901. Verr. 

 Brit. FL VIII, 498, 1, figs. 345-347. — 1907. Kat. palåarkt. Dipt. III, 96. 



— Syrphus tristis Fabr. 1794. Ent. Syst. IV, 303,92 et 1805. Syst. Antl. 

 245, (52 {Eristalis). — 1817. Fall. Dipt. Suec. Syrph. 29, 23 {Syrphus). 



Male. Eyes separated, vertex narrowing downwards to a little 

 below the middle, and from here the frons widening downwards so 

 that the horders of vertex and frons form an angle; vertex blackish, 

 brownish pruinose anteriorly with a dull blackish cross-band between 

 vertex and frons; frons and epistoma whitish grey pruinose, the cen- 

 tral knob, the upper mouth edge and the lower side margin, as well 

 as the jowls, black. Vertex with blackish, anteriorly brownish hairs, 

 frons with brownish or blackish, anteriorly whitish hairs, and epistoma 

 with whitish hairs. Epistoma hollowed below the antennæ, the knob 

 somewhat protruding and epistoma a little retreating below it; the 

 lower part somewhat protruding and descending. Occiput bluish black, 

 grey pruinose at the eye-margin except above, the hairs are vvhite 

 below, yellow above and here there is a row of black hairs. Eyes 

 brown with numerous dark or black, circular but more or less con- 



